1. Field of the Invention
The present invention relates to an apparatus for reducing the thickness of a piece of material, and, more particularly, is directed to a portable apparatus for planing wood.
2. Description of the Invention Background
Generally, a planer is used to finish a piece of lumber, i.e., to uniformly reduce the thickness of the lumber while achieving a smooth, flat surface. The basic components of a typical planer are a table, a cutterhead, infeed and outfeed rollers, and a motor. The table levels and supports the workpiece as the workpiece is fed into the planer and is passed under the rapidly rotating cutterhead. The cutterhead includes two or more knives secured within its cylindrical head which cut away thin slivers of wood as the workpiece is passed beneath it. The powered infeed and outfeed rollers grip and support the workpiece as they advance and pull the workpiece through the cutterhead. These rollers are typically spring mounted so that the pressure exerted by the rollers on the workpiece can be adjusted to ensure the rollers properly engage and guide the workpiece through the planer. The motor drives the cutterhead and the powered rollers.
Typical portable planers have only one cutterhead located above the planer table. Thus, both sides of the board must be passed through the planer to attain the desired finished surface. Additionally, several passes through the planer may be required to remove the desired amount of wood from the workpiece. For instance, portable planers, due to their size and weight, cannot remove more than 1/32 of an inch of stock in one pass for a finished cut and can remove about a maximum of 3/32 of an inch on a preliminary cut. Thus, several passes through the planer may be required to achieve a desired thickness of the workpiece. The depth of cut adjustments are made by lowering the cutterhead towards the workpiece or by raising the table, and thus the workpiece, towards the cutterhead.
Prior planers, particularly portable planers, cause damage to each end of the workpiece. In particular, when the workpiece is fed into the planer, it is initially only supported by the powered, spring mounted infeed roller. When the workpiece contacts the cutterhead, it is thrust against the cutterhead which causes the cutterhead to jump. This jumping action results in indentations or "snipes" being formed in at least the first few inches of the workpiece. The sniping discontinues when the workpiece is advanced further into the planer and is supported by both the infeed and outfeed roller. The support by both rollers prevents the workpiece from being thrust against the cutterhead. Similarly, as the workpiece exits the planer, and is supported only by the outfeed roller, the workpiece is again thrust against the cutterhead, causing it to jump. This jumping action again results in snipes being formed in the last few inches of the workpiece. Therefore, current planers cause damage to both the first and the last few inches of each end of a workpiece, which are therefore not useable as finished stock.
Thus, there is a need for a planar that can uniformly reduce the thickness of a workpiece without causing damage to each end of the workpiece.
There is a further need for a planer that is relatively lightweight and a portable.
There is yet another need for a planer with the above-mentioned attributes that is relatively inexpensive to manufacture.